壁面粗糙结构对颗粒沉积特性影响的数值研究

Numerical study on the influence of wall roughness on particle deposition characteristics

中文关键词: 气固两相流  CFD-DEM  颗粒沉积  粗糙壁面

英文关键词: Gas-solid two phase flow,CFD-DEM,Particle deposition,Rib-roughened surface

中文摘要:

      采用CFD-DEM方法对1~50μm颗粒在粗糙流道内沉积特性进行分析。主要研究了颗粒粒径、粗糙元形状（正方形、尖角、三角形）对沉积速率的影响。结果表明：受粗糙结构附近漩涡影响，粗糙壁面将小颗粒（τp＋<1）沉积速度提升至1~2个数量级，沉积速度比最高可达172。然而大颗粒（τp＋>1）受反弹效应影响导致颗粒沉积速度减小；由于不同形状粗糙元的迎风面和背风面与气流方向夹角不同，使得流道内流场速度波动以及粗糙元附近漩涡有明显变化，导致尖角形粗糙结构流道沉积速度最大，三角形粗糙结构流道沉积速率最小。

英文摘要:

      This paper presents a study of the characteristics of a 1~50 μm particle deposition in a rib-roughened channel using a combined computational fluid dynamics-discrete element method (CFD-DEM) The effects of particle size, roughness element shape (square, sharp corner, triangular) on the deposition ratio are study. The results show: the particles were affected by the eddies near rough elements. The small particles (τp＋< 1) increased greatly 1 ~ 2 orders of magnitude, the deposition rate than the maximum of 172. While the large particles (τp＋>1) affected by the rebound effect lead to particle deposition rate decreased. Due to the different angles between the windward and leeward surfaces of different rough elements and the flow di-rection， the velocity fluctuation of the flow field and the vortex around the rough elements change sig-nificantly, The deposition rate of a sharp-angle rough structure channel was the highest, while that of a triangular rough structure channel was the lowest.